Celebrating our wonderful wetlands
By Caitlin Ransom, SAEON Science Engagement and Communications Officer
By Caitlin Ransom, SAEON Science Engagement and Communications Officer
SAEON celebrated World Wetlands Day on 2 February 2022. This year’s theme, “Wetlands Action for People and Nature”, highlighted the importance of actions to ensure the conservation and sustainable use of wetlands for human and planetary health.
Using South African examples, Sue van Rensburg, coordinator of the SAEON Grasslands-Wetlands-Forests Node and Dr Julia Glenday, postdoctoral researcher at the SAEON Fynbos Node, took the learners on a journey to learn how to value, manage, restore and – most importantly – to love wetlands.
Wetlands come in all shapes and sizes. They are areas that are covered by water (or there is water near the surface). Water does not have to be there permanently for an area to be considered a wetland. These pans, which only get water every now and then, are also wetlands. They can have fresh water, such as vleis or flood plains, or they can have salty water, such as estuaries and salt marshes.
Learners were asked what they think of when when they hear the word ‘wetland’.
The theme for World Wetlands Day 2022, “Wetlands Action for People and Nature”, highlighted the importance of actions to ensure the conservation and sustainable use of wetlands for human and planetary health.
Wetlands around the world have been degraded, and this is no different in South Africa. Approximately 88% of South Africa’s wetland area is threatened with ecosystem collapse (SANBI, 2019). Globally we are losing wetlands three times faster than forests (Ramsar, 2019). Wetlands are critically important ecosystems for both people and nature, yet they are poorly protected. In South Africa, less than two percent of our wetland areas are considered well protected (SANBI, 2019).
The risk of ecosystem collapse is indicated by the threat status. The protection level indicators show how well ecosystem types are represented in the protected areas. (SANBI, 2019)
The loss of wetlands affects both people and the planet. Wetlands are extremely important ecosystems that contribute to freshwater availability, biodiversity, climate mitigation and adaptation, global economies and more.
Do you know where the water from your tap comes from? Well, the answer is likely a wetland.
The Kromme River in the Eastern Cape province supplies most of the water to Gqeberha and the surrounding towns and in its upper reaches there are palmiet wetlands. Wetlands purify water and act as sponges storing water. These characteristics mean they can help prevent floods and erosion and even release water during dry periods. Dr Julia Glenday created a model of a wetland to show the learners how the water balance works and how the “spongy” soils of wetlands can slow down and store water. Palmiet is an ecosystem engineer, not only does it change the river channel and how the water flows, but over hundreds of years the wetlands grow and widen the valley.
Wetlands can help us cope with climate change and its impacts. Their water storage ability could be vital in dealing with the rise in extreme events such as floods and droughts. Wetland soils, while wet, are also good at storing carbon removed from the atmosphere. The problem is when wetlands dry out and fires occur, like in the wetlands of the Maputaland coastal plain. These fires release huge amounts of greenhouse gases into the atmosphere. These are the gases that are responsible for climate change.
Wetlands are highly productive and home to remarkable biodiversity. They provide a home for many insects, fish, amphibians, birds and specialised plants. Wetland plants (such as palmiet) are able to survive in waterlogged soils, while most other plants will die under these conditions. This biodiversity also attracts tourists.
We therefore need to value wetlands for the nature-based solutions and multiple benefits they provide for a healthy planet and human well-being.
A palmiet wetland in the Kromme River. (Photo: Penisoh Metho)
Improving our understanding of wetlands and getting a grip on the consequences of change will go a long way in improving our ability to manage and restore wetlands in a sustainable manner.
A key threat to wetlands is land use change. Along part of the Kromme River, palmiet wetlands have been removed to make space for pastures and orchards. Drains were dug and the river channel was deepened so these farms (previously wetlands) no longer get flooded. But because the river is connected, these changes lead to erosion further upstream, impacting the wetlands that remain. The Working for Wetlands programme is trying to protect the remaining wetlands of the Kromme. Through building structures such as weirs and closing drains, they aim to stop the erosion from moving further upstream into the remaining wetlands.
A gabion weir built to protect the upstream wetlands from erosion. (Photo: Julia Glenday)
Forestry and exotic species pose another land use change threat to wetlands. The wetlands of the Maputaland Coastal Plain in Northern KwaZulu-Natal are a unique groundwater system. But there is a problem: the water table is dropping. One of the big drivers in the drop in the water table is the increase in forestry, specifically eucalyptus plantations. Because of the poor soils in this area, farming eucalyptus trees is often seen as the only source of income. These exotic trees use a lot of water.
The issues facing wetlands are not simple. We therefore need to get economists, climate scientists, hydrologists, social scientists and local communities (whose lives will be impacted) to work together. By taking this big picture approach using multidisciplinary teams, we can improve our understanding of the long-term consequences of how we manage our land and ultimately our wetlands. By managing and restoring these wetlands wisely and sustainably, we can conserve them and make sure these critically important ecosystems are healthy for both people and nature.
Lake Sibaya, the largest freshwater lake in South Africa, is found in the Maputaland Coastal Plain. Comparing these two photos (taken from the same place, the photo on the left in June 2015 and the photo on the right in February 2019), the drop in water level can be clearly seen. (Photos: Sue J. van Rensburg)
The roots of these trees can penetrate deep into the ground to access the water table, even as the water table drops. The grasses which are naturally found in this area have shallow roots. This means that water is only available to grasses when the water is near the surface. (Image: Caitlin Ransom; adapted from Sue J. van Rensburg)
South African National Biodiversity Institute (SANBI). 2019. National Biodiversity Assessment 2018: The status of South Africa’s ecosystems and biodiversity. Synthesis Report. South African National Biodiversity Institute, an entity of the Department of Forestry, Fisheries and the Environment, Pretoria. pp. 1–214.
Ramsar Convention on Wetlands. (Ramsar). 2018. Global Wetland Outlook: State of the World’s Wetlands and their Services to People. Gland, Switzerland: Ramsar Convention Secretariat.